ZoneCheck


This is quick test to determine if a DNS server is an Open Resolver.

DNS servers must only ever answer queries for authoritative domains, and local IP ranges, they must never answer for third parties.
The dangers in not doing so are many and serious, including DDoS attacks.


Enter a DNS Server Address (hostname or IP)
* Names default to IPv4
 

Challenge Response 11 + 4 =

 

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